1. Field
This disclosure relates to an electrode for measuring a bio potential, a method of manufacturing the electrode, and a system for measuring a physiological signal.
2. Description of Related Art
Recent healthcare systems improve accuracy and convenience of diagnosis by measuring various physiological signals in daily life. In particular, smart healthcare systems for providing health-related services through personal health information databases, helping medical staff to perform telediagnoses, and delivering results of diagnoses and prescriptions to patients are being introduced.
A human body is a conductor in which an electrical field is formed due to an action potential that is generated by electrical excitation of cells. Therefore, electrical characteristics of the internal part of a body may be measured by detecting a small amount of current or detecting a change in current with respect to external stimuli in the body.
Generally, various bio potentials, such as an electrocardiogram (ECG), an electromyogram (EMG), an electroencephalogram (EEG), galvanic skin resistance (GSR), electrooculography (EOG), body temperature, heartbeat, blood pressure, and body movement, may be measured by using such a principle, and an electrode for a living body is used to detect changes in such physiological signals.
FIG. 1 illustrates an example of an electrode for a living body attached to the skin of a user, and a portable measuring system. An electrode for a living body is a medium for connecting the skin of a user to a system for measuring a physiological signal (hereinafter, a physiological signal measuring system), and affects the quality of the measured physiological signals and user convenience. In daily life, in order for an electrode for a living body to be attached to the living body of a user and to measure physiological signals of the user all of the time, various technical problems with respect to accuracy of measurement, communication, power consumption, and the technical problems need to be resolved.
In order to always have a physiological signal measuring system on a living body in daily life, an area of an electrode that is in contact with the skin of the body needs to be minimized to reduce skin irritation. In addition, it is necessary to reduce motion artifacts to accurately measure physiological signals during exercise.
FIG. 2 illustrates an example of noise generated in a measured physiological signal due to a change in an interface caused by a movement of a body, and shows that a signal-to-noise ratio (SNR) of the measured physiological signal is reduced by the movement of the body.